The present invention relates to building foundations and in, particular pile foundations.
Alaska and the Northern Regions are besieged by permafrost and ice rich soils conditions that make the construction of effective and economical foundation systems very difficult and costly. Foundations constantly fail and cause extensive damage to housing and other structures. Although foundation systems have been designed to solve these problems, they are generally not economically feasible for homes, in particular, as well as many other buildings. The budgets available for the construction of housing is not adequate for the installation of elaborate piling or refrigerated systems used for large commercial structures. In fact, the majority of homeowners living in the permafrost regions of Alaska simply acquiesce to high maintenance and repair costs of their homes caused by foundation movement.
Two types of foundations are typically used for housing and light buildings constructed in areas having permafrost conditions. One is xe2x80x9cpost and padxe2x80x9d and the other is piling. Although the post and pad system may have many variations, it commonly consists of wood or steel posts designed and supported on treated timber footings. The houses using this system are subject to high vertical and differential movement. The annual freeze-thaw cycles and frost heaves under the pads cause movement resulting in structural stresses to the houses resulting in cracking wallboard, plumbing breaks, broken window seals and doors jamming and in some severe cases, almost total failure of the houses. Most post and pad systems are difficult to adjust once they have moved and trying to re-level the houses has been a major challenge.
Prior piling systems include wood piles, steel piles, round and H driven piles and thermopiles. Generally, these piling systems are far to expensive for housing and small projects because of high materials costs and the cost of heavy equipment such as augers and cranes to install piles at remote locations. Driven steel piles are generally the most economical of the pile systems but it has been costly to install reliable bond breakers on driven piles to prevent jacking. Jacking is characterized as a gradual uplift of the pile due to the freeze thaw action of the surrounding soil. The freeze thaw action causes the surrounding soil to grip the upper part of the pile and lifts it upward. The reason for this is that the soil near the surface has a much stronger adfreeze bond or grip on the pile than does the warmer soil at depth. Therefore, without bond breakers, steel piles can be problematic for use in foundations in permafrost regions. In these prior piling systems, when bond breakers are used, the top five to seven feet of soil around the pile has to be dug out or a large diameter hole is predrilled so the bond breaker can be attached after insertion of the pile into the soil, resulting in wasted time and expense.
In view of the foregoing it can be seen that there is a need for an effective and economical foundation system for housing and other buildings in permafrost regions.
Therefore, it is an object of the invention to provide an anti-jacking pile for use in foundation systems.
Another object of the invention is to provide a pile having an anti-jacking covering thereon to resist the effects of freeze-thaw cycles in permafrost regions.
Still another object of the invention is to provide a collar for facilitating driving of a pile into soil.
Yet another object of the invention is to provide a collar attached to a pile for preventing damage to an anti-jacking covering on the pile.
Still another object of the invention is to provide a method of installing a pile having an anti-jacking covering thereon.
Yet another object of the invention is to provide an adjustable leveling system as a long-term contingency so that the house can be re-leveled in the event of vertical movement.